More than half of drink-driving checkpoints scheduled to be carried out by gardaí last year never took place, the Irish Independent can reveal.

Officers are routinely cancelling checkpoints, even after they have been registered on the Pulse system.

Sources said there were a variety of reasons why checkpoints did not happen, including emergency calls.

"If a couple of people phone in sick, or if the weather is bad, then it would be legitimate not to go out," a source said.

However, they acknowledged there was also a likelihood that many did not happen because officers "simply decided not to bother".

The problem has now led to Garda management introducing a new section on Pulse, where the reason for cancellations must be recorded.

Scheduled Mandatory Alcohol Test (MAT) checkpoints are created on the Pulse system in advance, with an expectation that the results will be recorded after the event.

Sometimes, this does not happen for several days.

Regularly, these results are based on estimated figures because of inadequate record-keeping on the ground.

As part of the revelations earlier this week, it was stated: "An Garda Síochána was not accurately recording the measurement from the breath testing device prior to April 2016."

Last year, gardaí put in place a new paper-based recording and verification process for breath tests.

In November, a data recording IT upgrade was installed on the Pulse system.

It now forces personnel to record the serial number of the device used for each breath test, along with the meter reading before and after the checkpoint was concluded. Gardaí said they were "satisfied at this stage" that the new processes put in place last year were working and that the statistics compiled were "solid".

However, they have decided not to publish the figures until they are "satisfied that the processes are robust enough and consistent enough to stand up to scrutiny".

"While 2016/2017 data is reassuring, we will continue to closely monitor the data," they said. "If we are satisfied that the data is accurate and solid at the end of 2017, we will consider publishing data that we can verify."